Sunday, April 26, 2009

How does fat get absorbed and stored as fat?

Fat is absorbed in the intestine contained in chylomicrons and then secreted into lymphatics (1). The lymphatics drain the intestine, then lead to the thoracic duct and deliver the chylomicrons into the blood at a site of rapid blood flow (1). The rapidity is necessary to distribute the chylomicrons well preventing them from coalescing (1). Then lipoprotein lipase, which is attached to endothelial cell survaces in the lumen of capillaries, acts on the chylomicrones to liberate fatty acids via hydrolysis (1). The fatty acids are taken up by adipocytes and reesterified with glycerol 3-phosphate to form triacylglycerols and be stored as fat droplets (1).